Existing automotive jumper cable systems suffer from some deficiencies that affect the convenience and safety of their use. Especially for automotive service professionals this is a regular for three reasons. First, electrical connections need to be made quickly yet reliably for both mechanical grip and correct polarity when applying cable clamps to vehicle battery electrode posts. Also, the presence and hazards inherent in sparks and electrical arcing must be minimized; these are common when making and breaking electrical connections, and pose a risk both for human safety and due to the flammability of fumes and oily deposits that are common in engine compartments. In addition, most cable systems require users to position two vehicles in close proximity in order to re-charge the battery of one from the battery of the other, whereas this is not always possible or safe when the first vehicle has stalled on a busy highway, moreover a charge-providing vehicle may need placement at an awkward position for charging purposes.
In light of these and other difficulties, various features have been developed by others. For instance, to ensure proper polarity indicator lights and alarms have been introduced in various configurations to show a closed circuit. See, e.g., U.S. Pat. Nos. 4,217,534; 4,185,204; 4,488,147; 4,897,044; 5,180,310; 5,083,076; and 5,367,243. In addition, U.S. Pat. No. 4,449,089 provides a circuit that automatically switches from charging an internal battery to charging an external battery when the connection is correct, and that reverts to internal charging when the external battery is disconnected. U.S. Pat. No. 5,793,185 provides a hand-held charger unit that includes an internal battery, charger circuit that can accept AC or DC electrical sources, connections and controls to prevent overcharging and incorrect polarity. U.S. Pat. No. 5,820,407 teaches the use of half-wave rectifier-biased directional jumper cables for placing a discharged battery in parallel with a charged battery to increase the electrical energy available for charging. U.S. Pat. No. 6,799,993 provides a portable energy source in which a battery compartment has an opening, a cover, and a power inverter that is mechanically connected to the cover and when the cover is closed is electrically connected to the battery. U.S. Pat. No. 8,199,024 discloses a circuit that assesses polarity and whether it is safe to connect two low-voltage systems, and that if it is safe to do so then provides a “soft start” connection in order to minimize voltage spikes. U.S. Pat. App. Pub. No. 2005/0070155 teaches the use of jumper cable sections connected by hermaphroditic connectors at each end to ensure proper polarity and safe connections, and also includes a fusible component as a safety feature.
Matching voltages and/or amplitudes has also been addressed by various means. U.S. Pat. No. 6,679,708 teaches use of a junction box that prevents flow of high current during jump-starting and that has a convenient blade for attaching a jumper cable's positive lead. U.S. Pat. No. 7,508,163 teaches use of a rechargeable AC 110V portable power supply that can be used to jump start a dead vehicle battery either by a trickle charge or via the vehicle's lighter outlet. U.S. Pat. No. 7,795,838 provides a visual display of battery data and state of charge data for charging a high voltage battery in a hybrid vehicle. U.S. Pat. App. Pub. No. 2003/0085621 employs a power supply that detects device power requirements and adapts to provide it. Connections that isolate a device and its dead battery allow the power supply to recharge the battery in parallel with powering the device.
Among other strategies that have been employed, switch configurations have been introduced to reduce or eliminate sparking. U.S. Pat. No. 4,286,172 describes use of a relay at intermediate segments of jumper cables. The relay keeps the circuit open unless actuated by a solenoid that is in series with a push button switch and a relatively strong battery to which the cables are connectable. U.S. Pat. No. 4,489,223 employs a radio signal-actuated solenoid circuit to enable power transfer from the battery of a service vehicle to the battery of a second vehicle. U.S. Pat. No. 5,297,977 discloses uses of two paired sets of jumper cables that share a junction box and a manual switch for electrical flow.
In several cases workers have attempted to simply relocate any potential for sparking to a convenient location that is remote from the engine and battery. U.S. Pat. No. 4,274,690 discloses electrical connection of a vehicle battery to apertures in the vehicle's body panels, through which the battery may be jump started. U.S. Pat. Nos. 4,700,961 and 4,807,895 teach the use of electrical terminals in a cover-protected exterior compartment of a vehicle, to facilitate charging the vehicle's battery and quick starts without sparking near the battery. U.S. Pat. No. 5,013,259 describes an auxiliary unit designed for remote mounting from a battery to which it is connected, to facilitate connection with a jumper cable.
Various other innovations have been introduced to improve the convenience of jump starting. U.S. Pat. No. 4,079,304 describes the use of paired jumper cables on a reel. U.S. Pat. No. 4,667,141 discloses a jumper battery on a hand truck; discharge for use in jump started is actuated by a switching circuit that responds to a token or coin. U.S. Pat. No. 4,932,896 provides a jumper cable extension format having terminal through-holes at each end. U.S. Pat. No. 5,435,759 teaches a jumper cable clamp in which the jaw has—in addition to teeth—opposing half-round features such as for gripping a cable or wire. U.S. Pat. No. 5,597,331 describes a charging cable that employs at one end a pinch bolt and fastener to secure a clamp to a battery terminal post on a first battery, and that employs at the other end a transfer terminal for removable connection to a stud on a second battery, such that the first battery is not easily disconnected or accidentally loosened unless the second battery is disconnected first. U.S. Pat. No. 5,985,481 discloses a reserve battery based on aluminum anodes and chalcogen cathodes, and for which hydroxide electrolyte crystals that are released into the cell's solvent when needed, where the reserve battery is configured to jump-start or bypass the main battery.
Although each of these prior designs has useful features, nevertheless automotive professionals continue to need designs that cost less, enhance safety, facilitate rapid application and charging, and do not require specialized designs for the vehicles that are being surfaced. Thus there is an ongoing need for improved jump-starting systems.